A power supply that is often used in telecommunications, transportation, industry and other applications may require electrical isolation between an input and an output of the power supply. A transformer with a primary winding and a secondary winding is often used to provide this isolation; furthermore, the transformer may also include an auxiliary winding.
In a power converter (such as a switching power supply circuit), a driving power is provided into a driver (or controlling device) of the power converter. For example, a controlling power supply voltage (Vcc) from a rectifier circuit is provided into the driver as the driving power when the switching power supply circuit is started (or may be referred to as activated or initiated) and an output voltage from the auxiliary winding of the transformer is provided into the driver as the driving power when the switching power supply circuit is working (for example, on a steady operation state after being started).
On the other hand, the driver of the power converter may include a digital controller. For example, the driver may include a low voltage circuit (i.e. a digital micro controller) and a high voltage circuit.
Reference document 1: JP2015-103336A
Reference document 2: US2016/0365799A1
This section introduces aspects that may facilitate a better understanding of the disclosure. Accordingly, the statements of this section are to be read in this light and are not to be understood as admissions about what is in the prior art or what is not in the prior art.